Dispersible antimicrobial complex and coatings therefrom

ABSTRACT

Disclosed are latexes, suspensions, and colloids having a cationic antimicrobial compound complexed with an anionic surfactant. The surfactant may have greater affinity for the antimicrobial compound than other anionic surfactants and other anions in the latex, suspension, or colloid that contribute to disperse phase stability to prevent disrupting the dispersions. Dispersions containing the antimicrobial compound may therefore have a shelf life comparable to dispersions that are otherwise identical but lack the cationic antimicrobial compound and its complexed anionic surfactant. Coatings made with the complexes can exhibit essentially undiminished antimicrobial activity.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of allowed U.S. application Ser. No.16/938,680, filed Jul. 24, 2020 and entitled “Dispersible AntimicrobialComplex and Coatings Therefrom,” which is a Continuation of U.S.application Ser. No. 15/992,033, filed May 29, 2018, and entitled“Dispersible Antimicrobial Complex and Coatings Therefrom,” and whichclaims the benefit of priority to U.S. Provisional Patent ApplicationNo. 62/511,975, filed May 27, 2017, and entitled “Dispersible PolymericAntimicrobial,” the entire contents of each of which are incorporated byreference herein as if put forth in full below.

FIELD OF THE INVENTION

The invention relates to antimicrobial compounds containing cationicquaternary nitrogen that are compatible with surfactant stabilizedsuspensions and colloids including emulsion and latex formulations.

BACKGROUND

Various dispersants and surfactants have been developed so that smallnon-polar particles can be evenly dispersed within an aqueous or aqueousorganic carrier. These small particles can be organic or inorganic innature. Organic particles may include, but are not limited to, smallmolecule, monomeric, or polymeric entities. The particles may be solid,liquid, or gas. These formulations would include, but are not limitedto, dispersions used as binders, adhesives, sealants, or coatings.Inorganic particles may include, but are not limited to, variouspigments, thickeners or other materials that give the suspension,emulsion, latex, or colloid their desirable properties.

Dispersants and surfactants frequently consist of molecules having apolar hydrophilic head and a non-polar hydrophobic tail and are referredto as amphiphilic. Their mode of action involves the association of thehydrophobic tail with the non-polar material to be dispersed leaving thepolar head on the surface to interact with the polar solvent phase. Theexposed polar groups repel each other in those cases where the groupsare charged thus preventing the agglomeration of the stabilizedparticles. The dispersed nonpolar particles are suspended in the polaraqueous medium as individual entities. The polar heads of the surfactantand dispersant molecules are frequently functional groups bearing anegative charge although positive and non-charged species are alsopossible.

The absence or removal of surfactants or dispersants from the colloidwill frequently result in the association or agglomeration of thesuspended non-polar particles. The resulting aggregation of particleswill destabilize the colloid resulting in a non-homogeneous suspensionof limited utility.

One example of a water-based surfactant stabilized dispersion could be acomposition containing latex binders as well as mineral based pigmentsand other additives forming a coating that is applied to a surface forexample, a water-based emulsion or latex paint. The composition allowsone to apply a homogeneously dispersed matrix of particles and theirbinder evenly on a surface. Allowing the volatile components toevaporate forms a permanent coating of the dispersed particles and othercomponents present within the binder system.

There is a desire to add antimicrobial characteristics to suspensions,emulsions, latexes, and colloids that are stabilized by normallyavailable surfactants and dispersants. Unfortunately, the most commonlyavailable antimicrobials (quaternary ammonium, phosphonium, and othercationic materials) are frequently not compatible with these surfactantsand dispersants. The addition of these cationic species destabilizes thesuspensions by combining with the frequently used anionic head groups ofthe surfactants. The association of the cationic portion of theantimicrobial with the anionic head of the surfactant along with theassociation of the lipophilic portion of each species results in theformation of insoluble complexes of the antimicrobial and surfactant.These complexes are no longer capable of stabilizing the suspension asthey are effectively made unavailable, and the dispersed elements beginto agglomerate, flocculate or coalesce.

In one instance quaternary ammonium based antimicrobials have reportedlybeen successfully formulated into latex paints, however, this requirescareful selection of components and their relative concentrations inorder to minimize the instability of the suspension. See, e.g., U.S.Pat. No. 9,131,683.

In addition, it is particularly difficult to disperse particles ofvarious hydrophobic small molecules and polymers in water. Thehydrophobicity of the organic compounds causes the particles to rapidlyseparate from water and concentrate in the bottom of a container holdingthe particle-containing aqueous suspension. The polymeric particles havea much greater affinity for one another than water and often agglomeratetogether in the bottom of the container. It can be quite difficult tore-disperse these polymeric particles that have settled within thecontainer as a consequence of clumping. The non-homogeneity of theresulting suspension results in a non-homogeneous application and finalcoating.

This non-suspendability is also particularly true for many antimicrobialsmall molecules and polymers that are hydrophobic. In particular, therelatively high molecular weight of the polymer present within theparticles allows the polymer chains to intertwine, known as pseudocross-linking. The particles' relatively large size provides for largehydrophobic domains of substantial surface area to come in contact withone another when the particles settle from the aqueous carrier. Thelarge areas of hydrophobic polymer in contact with one another canprovide a strong binding force between particles. It can therefore bequite difficult to form a stable dispersion of these antimicrobialpolymers in an aqueous carrier to form e.g. a water-based paint that isantimicrobial.

BRIEF SUMMARY OF ASPECTS OF THE INVENTION

Among other embodiments, the invention provides cationic antimicrobialcomplexes that are dispersible in an aqueous carrier. The invention alsoprovides in some embodiments an amphiphilic antimicrobial material thatis compatible with surfactants and dispersants commonly used to makesuspensions, latexes, and colloids. The invention also provides methodsof making such particles as well as methods of dispersing surfactantcompatible antimicrobial particles.

A number of compositions are disclosed herein. One such composition maycomprise a mixture of a carrier liquid and at least first and secondcomplexes. The first complex is a cationic antimicrobial compoundcomplexed with an anionic surfactant. The second complex differs fromthe first one. The anionic surfactant of the second complex may be thesame as or may differ from the surfactant of the first complex, and thesecond complex may be in the form of particles (solid and/or immiscibledroplets) in the carrier liquid. The mixture may be in the form of asuspension and/or a colloid, such as a latex and/or an emulsion.

Another composition comprises a mixture of a carrier liquid and at leastone complex. This complex has a cationic antimicrobial polymeric portionand an anionic surfactant-compatibilizing portion, and the complex hasan ionic attraction between the cationic antimicrobial portion and theanionic surfactant-compatibilizing portion that is greater than an ionicattraction of either portion to any other ions present in the liquidcarrier. Preferably, the complex after removal of the liquid carrier hassufficient antimicrobial activity to substantially reduce the presenceof bacteria. Also preferably, the anionic surfactant-compatibilizingportion suspends the complex in the carrier liquid. Further; the mixturewithout addition of the complex is a suspension and/or a colloid, suchas a latex and/or an emulsion. Additionally, the mixture after additionof the complex remains a suspension and/or a colloid, such as a latexand/or an emulsion.

A composition as disclosed herein may comprise a liquid carrier and adispersion of antimicrobial complex having a plurality of molecules of acationic antimicrobial portion of the complex in a carrier liquidcontaining a dispersion. The cationic antimicrobial portion in thecarrier liquid is complexed to a first anionicsurfactant-compatibilizing portion derived from a first anionicsurfactant. The dispersion also has a second anionic surfactant, and thefirst anionic surfactant-compatibilizing portion has an ionic attractionto the cationic antimicrobial portion that is greater in magnitude thanan ionic attraction of the second anionic surfactant to the cationicantimicrobial portion. Preferably, the first anionicsurfactant-compatibilizing portion has an ionic attraction to thecationic antimicrobial portion that is greater than the ionic attractionof any anion in the carrier liquid to the cationic antimicrobialportion.

Any composition as described herein may preferably be formulated as anantimicrobial liquid coating composition, which may remain as a liquidwhen applied or may cure to form a solid coating on an object. One suchcoating composition may comprise a mixture containing a complex having acationic antimicrobial portion and a first anionicsurfactant-compatibilizing portion. The mixture may be a stablesuspension and/or a colloid, such as a latex and/or an emulsion. Thismixture contains more total surfactant (of the same or of a differenttype of surfactant) than a comparative suspension and/or colloid that isunstable in the absence of the first anionic surfactant-compatibilizingportion.

The invention also provides various methods of making a mixture. In oneembodiment, the invention provides a method of making a coating materialin which one disperses a complex as described herein in a carrier liquidthat contains a second anionic surfactant. The first anionicsurfactant-compatibilizing portion of the complex has an affinity forthe cationic antimicrobial portion of the complex that is greater thanor equal to the affinity of the second anionic surfactant to thecationic antimicrobial portion.

Another method of making a mixture comprises forming a first mixturecomprising a dispersion and/or colloid, such as a latex and/or anemulsion, with a dispersible antimicrobial complex as disclosed hereinto form a second mixture. The dispersible antimicrobial complex may beadded to the first mixture as a complex, or the complex may be formed inthe first mixture by adding an anionic surfactant and a cationicantimicrobial compound to the first mixture and mixing to form thedispersible antimicrobial complexes in the first mixture.

The invention also provides various methods of using a first anionicsurfactant. One such method prevents precipitation of cationicantimicrobial compound and/or destabilization of a suspension and/or acolloid, such as a latex and/or an emulsion. The method involves (a)adding a cationic antimicrobial compound to a mixture that includes asecond anionic surfactant, wherein the cationic antimicrobial compounddestabilizes a disperse phase in the mixture in the absence of additionof the first anionic surfactant and the mixture is a latex, asuspension, or a colloid; and (b) preventing the precipitation and/ordestabilization by adding the first anionic surfactant to the mixture toprevent the cationic antimicrobial compound from destabilizing thedisperse phase in the mixture. The cationic antimicrobial compound andfirst anionic surfactant may be added to the mixture separately or as apre-formed complex.

Other compositions, methods of making, and methods of using the newcomplexes disclosed herein are disclosed below.

DETAILED DESCRIPTION OF THE INVENTION

The invention in one instance provides dispersible antimicrobialcomplexes that can be dispersed and preferably suspended in either (a)an organic carrier such as oil or a dispersion in oil or (b) an aqueouscarrier such as water, a water-based solution, or an aqueous dispersion.A dispersion may have liquid or solid particles and can be in such formsas a suspension and/or a colloid such as a latex or an emulsion. Theparticles of dispersible antimicrobial complexes can be e.g. part of asolution or dispersion that can be applied to a surface to form acoating.

Dispersible antimicrobial complexes may have two portions, a cationicantimicrobial portion and an anionic surfactant-compatibilizing portion.These two portions complex together, with the ionic attraction of thetwo portions typically being greater than the attraction to other ionspresent in the solution (and preferably their ionic attraction beinggreater than the attraction to any other ions present in the solution).The ionic attraction of the two portions may also be such that the ionicstrength contributed by the complex to the entire solution is relativelylow—i.e. the concentration of either ion of the dispersible polymericantimicrobial particles in the carrier liquid is low but sufficient tosubstantially reduce the presence of bacteria without destabilizing thesuspension or colloid (in latex or emulsion form). The anionicsurfactant-compatibilizing portion is preferably sufficientlyhydrophilic to enable the entrainment of dispersible polymericantimicrobial particles in water to form a colloid (latex or emulsion)or sufficiently hydrophobic to enable the entrainment in an organicliquid to form a colloid, as discussed further below.

A dispersible antimicrobial complex may be present in its carrier liquidas e.g. an individual molecule or as a liquid or solid particle. Theseparticles may be on the order of e.g. several nanometers to severalmicrons in size, for instance.

The molar ratio of cationic antimicrobial portion to anionicsurfactant-compatibilizing portion may be e.g. about 1:1 to 1:1.2. Aslight excess of surfactant can help to retain complexes in suspensionin their carrier liquid, particularly if the cationic antimicrobialportion is polymeric. However, an excess may cause destabilization ofother colloids or suspensions present in the carrier liquid.Consequently, one should adjust the amount of anionicsurfactant-compatibilizing portion accordingly.

Cationic Antimicrobial Portion

The cationic antimicrobial portion is an ionic form of a cationicantimicrobial compound that has an anion (e.g. a halide such as Cl⁻ orBr⁻) associated with it. The cationic antimicrobial compound may be asmall molecule whose chemical formula is not represented by repeatedmonomers or comonomers, an oligomer of e.g. 2-4 monomers or comonomersthat have been copolymerized to form the oligomer, or a polymerhaving >4 monomers or comonomers that have been copolymerized to formthe polymer, for instance. The cationic antimicrobial compound as usedin the invention may also be a mixture of these compounds.

The cationic antimicrobial compound may be more easily dissolved orsuspended in its carrier liquid when complexed with its correspondinganionic surfactant. For instance, a cationic polymeric antimicrobialcompound may be a homopolymer of e.g. 4-vinylpyridine that has beenquaternized with e.g. 1-bromohexane or 1-chlorohexane. Correspondinganionic surfactants as discussed below can aid in dissolving ordispersing this hydrophobic antimicrobial compound in an aqueouscarrier.

The cationic antimicrobial compound may be one that is antimicrobial dueto a quaternized nitrogen and/or phosphorous being present in thecompound. These compounds can exhibit very good antimicrobial behavior,and in limited circumstances as discussed below, may be biocompatible.The nitrogen or phosphorous of the cationic antimicrobial compound maybe quaternized with hydrogen or with an alkyl, for instance. Preferablythe alkyl is a linear alkyl having between 4 and 12 carbon atoms, with 4and 6 carbon atoms being preferred. Such alkyl groups may be used inother of the antimicrobial compounds as well.

Polymeric cationic antimicrobial compounds are preferred when forming acomplex of the invention. The complexes formed using polymeric cationicantimicrobial compounds are typically particles as dispersed in theircarrier liquid. These compounds can have properties similar toproperties of other particles in the carrier liquid, and polymericcompounds also typically have high antimicrobial activity because of thelarge number of cationic active sites that can be incorporated into thepolymeric compounds.

The cationic antimicrobial portion may be a polymeric cation thatpossesses nonionic polar portions but in a number insufficient to enablethe cationic polymeric antimicrobial portion to remain dispersed in anaqueous carrier. The anionic surfactant-compatibilizing portion will bepresent to increase the overall polarity of the polymer throughformation of a complex of increased solubility but in dynamicequilibrium with an aqueous carrier such that sufficient antimicrobialis present in a suspension or colloid to be effective but notdestabilize the suspension or colloid. The anionic surfactant used maycontain a large number of nonionic polar groups to aid in forming thesuspension or colloid.

Optionally the cationic polymeric antimicrobial portion may behydrophilic and partially or completely soluble in aqueous media. Thehydrophilicity of the cationic polymeric antimicrobial portion cancomplement the hydrophilicity of the anionic surfactant portion to aidin maintaining the complex as part of a colloidal suspension. Thehydrophilicity introduced by way of a hydrophilic comonomer can also aidin maintaining the cationic polymeric antimicrobial portion in solutionin an effective amount to maintain the solution as antimicrobial. Adiscrete hydrophilic domain can be formed in the cationic polymericantimicrobial portion by copolymerizing antimicrobial monomers withhydrophilic monomers in a random or block polymerization reaction. Someparticularly useful hydrophilic monomers are HEMA, PEGMA, and PEGMEMA,for instance.

A hydrophilic cationic antimicrobial portion may also provide a largerset of surfactants that can be used to form complexes. Some surfactantsare not sufficiently hydrophilic to disperse hydrophobic cationicantimicrobial portions in the carrier liquid. However, the combinedhydrophilicity of the cationic antimicrobial portion and the surfactantmay together be sufficient to disperse them in the carrier liquidwithout precipitation and while maintaining antimicrobial efficacy.

An example of a cationic antimicrobial compound containing a hydrophiliccomonomer would be a random or block copolymer of a hydrophobic vinylpyridine such as 4-vinylpyridine and a hydrophilic monomer e.g.(2-hydroxyethyl) methacrylate, poly(ethylene glycol) methacrylate,and/or poly(ethylene glycol) methyl ether methacrylate, that has beenquaternized with e.g. an alkyl halide having e.g. between 4 and 12carbon atoms (preferably a linear alkyl) such as butyl bromide as isdisclosed in e.g. U.S. Pat. No. 8,343,473 issued Jan. 1, 2013 entitled“Hydrophilized Antimicrobial Polymers”, which is incorporated byreference in its entirety for all that it teaches and for all purposesherein (this patent is therefore to be treated as if this patent isrepeated in full below). The anionic surfactant-compatibilizing portioncomplexed to such a cationic polymeric antimicrobial portion can help todiminish or prevent the cationic polymeric antimicrobial portion fromdestabilizing other colloidal, dispersed, or dissolved components in theaqueous media as well as help to disperse the complex in the liquidcarrier.

A copolymer as described above can help to overcome a common problemincorporating cationic antimicrobial compounds into a colloid such as alatex or an emulsion. The cationic antimicrobial compounds that lackhydrophilicity often quickly precipitate from the coating solution intowhich the antimicrobial compounds are incorporated, thereby losingantimicrobial efficacy. These cationic antimicrobial compounds lackinghydrophilicity also can destabilize other colloidal particles in e.g. aliquid coating material and render the mixture worthless in a shorttime. A copolymer of e.g. a cationic antimicrobial monomer andhydrophilic comonomer can help to overcome one or more of theseproblems.

The cationic polymeric antimicrobial compound of U.S. Pat. No. 8,343,473may, in some instances, exhibit low toxicity so as to be biocompatible.For instance, the hydrophilic comonomer of a quaternized nitrogen- orphosphorous-containing cationic antimicrobial portion may be apoly(ethylene glycol methacrylate) (“PEGMA”), and in a particular formthis PEGMA may be poly(ethylene glycol methyl ether methacrylate)(“PEGMEMA”). A liquid coating material incorporating one or more of thebiocompatible cationic polymeric antimicrobial compounds and theresultant dry coating are also biocompatible. Such biocompatiblecoatings are often preferred for making objects used in hospitals andhouseholds.

Other examples of cationic antimicrobial portions are e.g.N-alkyl-N,N-dimethyl-benzyl ammonium and N,N-dialkyl-N,N-dimethylammonium. The cationic antimicrobial portion may be soluble in water,and its compatibility with external surfactants can be increased byvirtue of the anionic surfactant-compatibilizing portion that complexesthe cation sufficiently to prevent removal of surfactant necessary todisperse antimicrobial compound (e.g. particles) into the aqueous matrixwithout destabilizing the suspension.

Useful examples of quaternary ammonium compounds include, but are notlimited to n-alkyl (C8-C18) dimethyl benzyl ammonium chlorides,benzalkonium chloride (where the alkyl side chain is C8, C10, C12, C14,C16 or C18 or mixtures thereof), n-alkyl (C8-C18) dimethyl ethylbenzylammonium chlorides, dialkyl dimethyl ammonium chlorides (where the alkylside chain is C6-C12), n-alkyl dimethyl benzyl ammonium chloride, anddi-decyl dimethyl ammonium chloride, octyl decyl dimethyl ammoniumchloride, dioctyl dimethyl ammonium chloride, didecyl dimethyl ammoniumchloride, and mixtures of same.

The cationic antimicrobial compounds discussed above that form theantimicrobial cationic portion of a complex can be individual moleculesor small groups of molecules and, in some instances, may be polymerparticles having a particle size on the order of microns or tens ofmicrons. The density of these particles may differ from the density ofthe liquid in which the particles are suspended, allowing the particlesto concentrate and agglomerate over time. The anionic surfactant can aidin suspending these particles as well as help to prevent the cationicantimicrobial compounds from complexing or otherwise interacting withsurfactant associated with other particles to destabilize the colloid,suspension, or latex in which the cationic antimicrobial compounds aredispersed.

Anionic Surfactant-Compatibilizing Portion

The anionic surfactant-compatibilizing portion is an anion of an anionicsurfactant compound. The anionic surfactant-compatibilizing portionhelps to reduce the interaction of the cationic antimicrobial portionwith other surfactant used in the liquid mixture into which the complexis introduced. The anionic surfactant-compatibilizing portion also helpsto maintain the equilibrium concentration of all anionic stabilizers insolution, including the anionic surfactant-compatibilizing portion.Consequently, the cationic antimicrobial portion is less prone todestabilizing any disperse phase in the liquid mixture containing thecationic antimicrobial portion.

The anionic surfactant-compatibilizing portion typically has ahydrophobic part and a hydrophilic part. The hydrophobic part generallyassociates with the cationic antimicrobial portion, and the hydrophilicpart associates with an aqueous carrier liquid or with a disperse waterphase in an organic carrier liquid. The hydrophobic part may be aromaticor olefinic, for instance, and preferably the hydrophobic part has atleast 6 carbon atoms and more preferably at least 8 carbon atoms. Whenaromatic, the aromatic part (e.g. a benzyl group) may have a hydrophobicsubstituent such as an alkyl (linear or branched) having between 1 and12 carbon atoms, and more preferably having at least 6 carbon atoms.

The particular anionic surfactant-compatibilizing portion may beselected based on other surfactants present and the effect ofintroducing the anionic surfactant-compatibilizing portion on otherdispersed materials in the carrier liquid. The anionicsurfactant-compatibilizing portion may be identical to other surfactantpresent in the carrier liquid and used to help disperse other compoundswithin the carrier liquid to help minimize destabilization of otherdispersions. Otherwise, the anionic surfactant-compatibilizing portionmay have the same anions and similar non-polar domains as are found inother anionic surfactants to help prevent destabilization.Alternatively, the anionic surfactant-compatibilizing portion may havean anion whose pKa and molecular weight are similar to pKa and molecularweight of other anionic surfactants in the carrier liquid.

The overall polarity of the antimicrobial cationic portion is typicallyreduced when a complex is formed. The solubility of the dispersibleantimicrobial complex may also be reduced as a consequence, but thedispersible antimicrobial complex may remain in dynamic equilibrium withthe liquid of the liquid mixture (e.g. a latex, suspension, or colloid)such that sufficient cationic antimicrobial compound is present in theliquid mixture due to the presence of the anionic surfactant to beeffective but not destabilize the liquid mixture.

The anionic surfactant-compatibilizing portion may have a polar portionor portions in addition to the anionic center that binds the anionicsurfactant-compatibilizing portion to the cationic polymericantimicrobial portion. The anionic surfactant-compatibilizing portionmay have one or more electronegative and/or electropositive atoms in theanionic surfactant-compatibilizing portion to aid in dispersing thepolymeric antimicrobial particles within the coating composition. Theanion itself may provide sufficient hydrogen bonding to disperse thepolymeric antimicrobial particles. Alternatively, the anionicsurfactant-compatibilizing portion may not have sufficienthydrophilicity alone to suspend particles unless those particles alsocontain hydrophilic groups as discussed above.

The anionic surfactant-compatibilizing portion does not interferesubstantially with antimicrobial activity of the cationic polymericantimicrobial portion present in solution. The anionicsurfactant-compatibilizing portion may itself be a surfactant that iscapable of stabilizing the disperse phase, enabling the exchange ofstabilizers between the disperse phase and the cationic antimicrobialcompound without affecting the stability of the suspension. This may beparticularly true where the anionic surfactant-compatibilizing portionis the same surfactant used to stabilize other components present in thecarrier liquid with the dispersible antimicrobial complex.

The anionic surfactant-compatibilizing portion may also be antimicrobialin its own right, thus adding potentially broader scope of efficacy.Examples of such compatibilizers include but are not limited to fattyacids, e.g. lauric acid, octadecenoic acid, octadeca-dienoic acid;sulfonic acids and amides, e.g. 4-dodecylbenzenesulfonate and/orsaccharinate.

The anionic surfactant-compatibilizing portion can be any one or more ofthe following or its salt, for instance:

-   -   a. Phosphonates such as hexylphosphonate, dodecylphosphonate,        octadecylphosphonate and their mono methyl esters or similar        aliphatic, aromatic or heterocyclic mono esters.

-   -   Where R¹=H, linear or branched chain alkyl groups or mixtures of        groups having 1-7 carbons and R²=linear or branched chain alkyl        groups or mixture of groups having 6-20 carbons, benzyl or        C1-C18 alkyl benzyl groups    -   b. Sulfonates such as e.g. toluenesulfonate, benzenesulfonate,        dodecylbenzenesulfonate

-   -   Where R¹=linear or branched chain alkyl groups or mixture of        groups having 6-20 carbons, benzyl or C1-C18 alkyl benzyl        groups. R¹ groups may also contain halogen such as fluoride,        chloride, bromide, or iodide as well as one or more hetero atoms        such as nitrogen, oxygen, phosphorus, or sulfur    -   c. Sulfate Monoesters such as lauryl sulfate, sodium lauryl        sulfate, dodecyl sulfate, sodium dodecyl sulfate

-   -   Where R¹=linear or branched chain alkyl groups or mixture of        groups having 6-20 carbons, benzyl or C1-C18 alkyl benzyl        groups. R¹ groups may also contain halogen such as fluoride,        chloride, bromide, or iodide as well as one or more hetero atoms        such as nitrogen, oxygen, phosphorus, or sulfur.    -   d. Benzoate such as benzoic acid, sodium benzoate, alkyl benzoic        acid

-   -   Where R¹ may be placed at the 2, 3, or 4 position in the case of        monosubstituted rings and in the 2, 3, 4, 5, or 6 position in        disubstituted or higher rings. R¹ may be saturated or        unsaturated, linear or branched chain, cyclic alkyl groups or        mixture of groups having 6-20 carbons, benzyl or alkyl        substituted benzyl group R¹ groups may also contain halogen such        as fluoride, chloride, bromide, or iodide as well as one or more        hetero atoms such as nitrogen, oxygen, phosphorus, or sulfur.    -   e. Carboxylates such as stearic acid, palmitic acid, myristic        acid, undecanoic acid, undeceneoic acid.

-   -   R¹ may be saturated or unsaturated, linear or branched chain, a        cyclic alkyl group or mixture of groups having 6-20 carbons each        or, benzyl or alkyl substituted benzyl groups. R¹ groups may        also contain halogen such as fluoride, chloride, bromide, or        iodide as well as one or more hetero atoms such as nitrogen,        oxygen, phosphorus, or sulfur.    -   f. Glycolic moiety such as glycolic acid and other longer chain        alpha-hydroxy acids

-   -   R¹ may be saturated or unsaturated, linear or branched chain, a        cyclic alkyl group or mixture of groups having 6-20 carbons each        or, benzyl or alkyl substituted benzyl groups. R¹ groups may        also contain halogen such as fluoride, chloride, bromide, or        iodide as well as one or more hetero atoms such as nitrogen,        oxygen, phosphorus, or sulfur.    -   g. In general other anionic species of sufficiently high        polarity to aid in dispersing the antimicrobial particles.

Making Complex of Cationic Antimicrobial Compound and Anionic Surfactant

The anionic surfactant to be complexed with the cationic antimicrobialcan be selected from a list of common soaps and detergents. The anionicsurfactant used in a particular mixture preferably has equivalent orgreater ionic attraction for the cationic antimicrobial compound addedto the liquid mixture than all other anions that are present in themixture and that contribute to stability of the disperse phase in themixture. Ideally the anionic surfactant should be similar or identicalto that used to produce the colloid to be treated. The surfactant can becompounds bearing a sulfate, sulfonate, phosphate ester, or carboxylateof the type mentioned earlier.

The complex may be formed and subsequently added into a mixture that isto contain the complex. For instance, a first solution of dispersibleantimicrobial complex or particles may be formed using a cationicquaternized antimicrobial compound in the form of a small molecule andbearing an exchangeable counterion such as a halogen anion. A secondsolution of surfactant containing an anionic form (e.g. salt such as agroup I-ion salt) of a surfactant type listed above may be rapidly mixedwith the first solution to form the complex. This complexing reactioncan proceed in e.g. solution in a polar solvent such as isopropylalcohol, ethanol, methanol, acetone, or water. The reaction preferablyproceeds at a pH of about neutral. The pH is preferably between e.g. 2.0and 9.0, more preferably between 5.5 and 6.5. The complex can then beconcentrated or isolated from its solution and added to a solution orliquid mixture containing a disperse phase. Often, the small-moleculecomplex can precipitate, and the precipitate can be isolated and washedprior to incorporating it into a carrier liquid.

A polymeric dispersible antimicrobial complex can be formed similarly.For instance, cationic antimicrobial compound in powdered form may bedissolved rapidly in a solution containing excess surfactant underconditions as discussed above, and the resultant solution can be usedas-is with other stabilizers in solution or can be treated using methodsknown to those in the field to isolate complexes from excess surfactant.

The antimicrobial complexes are easily dispersed. Dispersion of theantimicrobial complexes can be accomplished using techniques commonlyused in the preparation of coatings such as high shear mixers or mediamill.

The complex may also or instead be formed in a solution or liquidmixture having a disperse phase without destabilizing the solution ormixture. For instance, anionic surfactant and cationic antimicrobialcompound may be added to a solution or mixture having a disperse phasesimultaneously using good agitation to blend the components, therebyrapidly forming a complex of the cationic antimicrobial and anionicsurfactant in the mixture while preserving any disperse present in theoriginal mixture. In some instances, the anionic surfactant flow mayprecede simultaneous addition of anionic surfactant and cationicantimicrobial compound as long as the flow and/or amount of surfactantadded does not destabilize the disperse phase or cause precipitation.Alternatively, small quantities of each may be added alternately (e.g. asmall quantity of anionic surfactant followed by a small quantity ofcationic antimicrobial compound) to avoid destroying the originaldispersion present in the mixture or to avoid precipitating a desirableion or compound to be retained in the solution. If needed, additionalcompounds or buffers may be added to maintain pH of the mixture to avoiddestabilizing it and precipitating materials that should remain insuspension or solution. One can employ the techniques used in preparingcoatings when preparing solutions or mixtures of the invention.

A coating material also typically contains a surfactant that stabilizescoating particles dispersed in the coating solution. A new coatingmaterial can therefore be formed by adding a dispersible antimicrobialcomplex as disclosed herein to the pre-existing coating material thatcontains the surfactant stabilizing coating particles. In this case, theaffinity of the cationic antimicrobial portion of the complex for theanionic surfactant-compatibilizing portion is greater than or equal toits affinity to the surfactant that stabilizes the coating particles.

The above-described methods of forming dispersible polymericantimicrobial particles can therefore involve the combination of abiocompatible antimicrobial cation with an anion which forms a complexwith the cation. The anion which in this case is sufficiently polar todisperse the particles in the aqueous carrier, particularly whereparticles have low solubility in water.

The antimicrobial-surfactant complexes may organize into micelles and/orassociate loosely or not at all in the mixture while remaining dispersein the aqueous mixture. If micelles form, the cationic antimicrobialportions of the complexes reside at exposed surfaces of the micelleswhen complexed to surfactant. The cationic antimicrobial portions aretherefore available to inactivate microbes in their liquid mixture or ina dried or cured coating formed from the mixture.

Dispersion stability was demonstrated, in one instance, by the additionof 1.0 gram of a random copolymer having 10 mol % poly(ethylene glycol)methyl ether methacrylate and 90 mol % N-hexyl-4-vinyl pyridiniumstearate to 30 grams of white latex paint and 30 grams of distilled typeII water, and the sample was visually observed over a period of 21 days.There was little or no evidence of excess separation of the dispersionduring this period when compared to a similarly prepared controlsuspension.

The coating composition may be e.g. a paint formulation containing, inaddition to the dispersible antimicrobial polymer, any one or more ofthe following components:

-   -   a. Pigment and/or dye such as TiO₂, calcium carbonate, talc,        clay, silicates, aluminum silicates, calcium metasilicates,        aluminum potassium silicates, magnesium silicates, barium        sulfates, nepheline syenite, feldspar, zinc oxides or sulfides,        functional fillers such as intumescent ingredients, such as        ammonium polyphosphates, melamines, pentaerythritol and similar        compounds.    -   b. Surfactants such as cetylpyridinium bromide, benzalkonium        chloride, stearic acid, alkyl ether phosphates, polyoxyethylene        glycol ethers, sodium lauryl sulfate, dodecylbenzene sulfonate.    -   c. Thickeners such as urethane thickeners and acrylic thickeners    -   d. Synthetic organic materials might also be incorporated; these        include plastic beads, hollow spheres or other similar        materials. Other optional components include glycols such as        ethylene and/or propylene glycol in amounts up to about 7% and        other solvents such as diethylene glycol dibenzoate and        dipropylene glycol dibenzoate in amounts up to about 3%. The        coating composition may also contain pigment dispersing agents        which can be solvents or surfactants; wet paint preservatives;        dry film preservatives; foam control agents such as oils, fatty        acids and silicones; slip and mar additives; adhesion promoters,        and/or other known paint additives.    -   e. The paint composition of the present invention may also        comprise other biocides including but not limited to metal ion        containing compounds, polymeric biocides, heterocyclic        compounds, phenols, organometallics, aldehydes, proteins,        peroxygens, alcohols, enzymes, polypeptides, and halogen        releasing compounds.

The coating solution may preferably have a pH of about neutral pH. ThepH is preferably between e.g. 2.0 and 9.0, more preferably between 5.5and 6.5.

Other coating solutions into which the dispersible polymericantimicrobial particles may be incorporated include inks, floor waxes,and furniture polishes.

An ink formulation typically has organic and/or inorganic pigmentparticles dispersed in a continuous aqueous, aqueous-organic, or organicphase, along with such other components as resins, surfactants, fillers,preservatives, and/or wetting agents. An example of such an inkformulation is one that has acrylic polymers, aliphatic polyurethane,and aliphatic polyester polyurethane resins as stabilized emulsions ordispersions. The formulation also includes, organic solvents, pigments,as well as photo-initiators as disclosed in U.S. Pat. Appl. No.2012/0046378 A1, which application is incorporated by reference in itsentirety.

Floor wax is typically a dispersion of a polymer that imparts the floorwax's finish, a polymer binder, and various coalescents and plasticizersand other components in an aqueous continuous phase. An example of sucha floor wax is one that has styrene-ethyl acrylate-methyl methacrylatecopolymer emulsion, polyethylene emulsion, tricresyl phosphateplasticizer, and styrene-maleic copolymer as disclosed in e.g. U.S. Pat.No. 3,328,328, which patent is incorporated by reference in itsentirety.

A furniture polish may contain one or more of the following hydrophobicmaterials dispersed in an aqueous phase: carnauba wax, candelilla wax,sugar cane wax, cotton wax, beeswax, shellac, lanolin fractions fromsheep, ozokerite, paraffin waxes, microcrystalline waxes, oxidizedmicrocrystalline waxes, Fischer-Tropsch waxes, montan waxes, polymerssuch as methyl acrylate, ethyl acrylate, butyl acrylate, vinyl acetate,styrene, vinyl chloride, acrylonitrile, and oils such as those derivedfrom vegetable, petroleum, or silicone sources to enhance shine. Anexample of such a furniture polish is one that has a silicone fluid,polydimethylsiloxanediol, a phosphonic acid dispersant, an oil in watersurfactant, and water as disclosed in U.S. Pat. Appl. No. 2013/0109794A1, which application is incorporated by reference in its entirety.

Dispersion stability may be measured using e.g. a turbidimeter ornephelometer to gauge whether the dispersion meets a desiredspecification for a particular composition. Stability may also bemeasured using the method described below.

The stability of the above described compositions can be compared usinga method similar to that described in U.S. Pat. No. 9,131,683 B2executed as follows:

Untreated coating preparation: Selected commercially available andproprietary coatings were diluted to approximately 25% weight solidswith type II distilled water. The diluted coating was agitated to ensurea homogeneous suspension. Enough suspension is made to supply test aswell as control samples.Dispersible quaternary ammonium compound preparation: Previouslyprepared dispersible quaternary ammonium compounds were suspended at aknown concentration in type II distilled water. Enough suspension ismade to supply test as well as control samples.Stability test: 20.0 g of diluted coating was mixed with sufficientdiluted quaternary ammonium compound to yield a concentration ofapproximately 1.0% active quaternary ammonium compound in the 20.0 gcoating. The mixture is placed in a graduated plastic 35 mL tube. Themixture is covered and then agitated to ensure homogeneity of thesuspension. The suspension is then allowed to sit at room temperature.The suspension is observed over a period of at least one week for anysettling of the suspension. Any settling is noted as mL of free liquidvs. the total volume of test suspension added to the tube. Theseobserved settling values are compared to a contemporaneously preparedcontrol sample that is of the same concentration.

The antimicrobial effectiveness can be determined by standardmicrobiological methods. In this case the method used was JIS Z 2801.The method was used as written without significant modification

It should be noted that in order to make any coating formulation, anappropriate dispersant/surfactant system is needed in order to dispersethe pigments in the paint formulation. The process for selectingdispersants/surfactants for paint formulations is well known to those ofordinary skill in the paint formulation art. After or during selectionof a compatible coating system and quaternary ammonium compound asdescribed herein, one of ordinary skill in the art would be able toselect a dispersant/surfactant combination in order to make a desiredpaint composition.

It is quite surprising that a biocompatible antimicrobial polymer can beconfigured as a dispersible solid. Typically, antimicrobial compoundshave a halide anion that is needed to assure that the compounds remainantimicrobial. We have determined, however, that antimicrobial polymerscan in fact be configured to be biocompatible as well as dispersiblewithout sacrificing antimicrobial properties. Consequently, a wide arrayof coatings as disclosed herein can be formulated using dispersiblepolymeric antimicrobial particles as disclosed herein.

Further, as discussed previously, the antimicrobial polymer has anaffinity for surfactant molecules, particularly the cation that has anaffinity for anionic surfactant molecules despite the presence of ahalide such as a bromide or chloride at the cationic site of thecationic antimicrobial portion. When the antimicrobial polymerencounters a surfactant molecule and joins to it, the resultant productprecipitates and settles. The surfactant molecule loses its ability tofunction as a surfactant, thus losing the ability to disperse polymer inan aqueous environment. The anionic surfactant-compatibilizing portionof dispersible antimicrobial complexes of the invention is selected inthis invention to provide particles with much less affinity forsurfactant molecules due to a lower rate of exchange of theantimicrobial polymer's anion with surfactant molecules. The anionicsurfactant-compatibilizing portion also modifies the polarity of theparticles to a sufficient level that the modified antimicrobialparticles are dispersible in the aqueous continuous phase.

Additional Examples

Following are specific examples of the invention to supplement thediscussion and examples discussed above. The specific examples discussedherein are not limiting on the scope of the invention and are providedto guide persons skilled in this field in forming complexes andmixtures.

Table 1a provides various examples of polymeric cationic antimicrobialcompounds and Table 1b provides various examples of nonpolymeric orsmall-molecule cationic antimicrobial compounds. Examples of compoundsprovided in Table 1b are benzyl tris(2-hydroxyethyl) ammonium chloride(#18) and tetrakis-hydroxymethyl phosphonium sulfate (#25). Table 2provides various examples of anionic surfactant that can be used to formcomplexes. Tables 3a and 3b have examples of complexes formed using thecompounds of Tables 1a, 1b, and 2. Table 4 provides examples of selectcomplexes in different products that are made using mixtures containingthe complexes. Other complexes of Tables 3a and 3b can be used insimilar mixtures.

Examples from Table 4 were used in efficacy tests. The results of suchtests are provided in Table 5 and exhibit excellent antimicrobialactivity.

TABLE 1a Examples of polymeric cationic antimicrobial compounds for usein the invention Moles Moles Monomer Monomer No. Monomer 1 Monomer 2Quaternizer 1 2  1 4-VP HEMA 1-bromohexane 0.9 0.1  2 4-VP PEGMEMA 3001-bromohexane 0.9 0.1  3 4-VP PEGMEMA 1000 1-bromohexane 0.9 0.1  4 4-VPPEGMA 300 1-bromohexane 0.9 0.1  5 4-VP PEGMA 1100 1-bromohexane 0.9 0.1 6 4-VP HEA 1-bromohexane 0.9 0.1  7 4-VP HEMA 1-bromohexane 0.6 0.4  84-VP PEGMEMA 300 1-bromohexane 0.6 0.4  9 4-VP PEGMEMA 10001-bromohexane 0.6 0.4 10 4-VP PEGMA 300 1-bromohexane 0.6 0.4 11 4-VPPEGMA 1100 1-bromohexane 0.6 0.4 12 4-VP HEA 1-bromohexane 0.6 0.4 134-VP HEMA 1-bromohexane 0.3 0.7 14 4-VP PEGMEMA 300 1-bromohexane 0.30.7 15 4-VP PEGMEMA 1000 1-bromohexane 0.3 0.7 16 4-VP PEGMA 3001-bromohexane 0.3 0.7 17 4-VP PEGMA 1100 1-bromohexane 0.3 0.7 18 4-VPHEA 1-bromohexane 0.3 0.7 19 N,N-DMAA HEA Hexyl Tosylate 0.9 0.1 20 4-VPHEMA 1-Chlorohexane 0.9 0.1 21 4-VP PEGMEMA 300 1-Chlorohexane 0.9 0.122 4-VP PEGMEMA 1000 1-Chlorohexane 0.9 0.1 23 4-VP PEGMA 3001-Chlorohexane 0.9 0.1 24 4-VP PEGMA 1100 1-Chlorohexane 0.9 0.1 25 4-VPHEA 1-Chlorohexane 0.9 0.1 26 4-VP HEMA 1-Chlorohexane 0.6 0.4 27 4-VPPEGMEMA 300 1-Chlorohexane 0.6 0.4 28 4-VP PEGMEMA 1000 1-Chlorohexane0.6 0.4 29 4-VP PEGMA 300 1-Chlorohexane 0.6 0.4 30 4-VP PEGMA 11001-Chlorohexane 0.6 0.4 31 4-VP HEA 1-Chlorohexane 0.6 0.4 32 4-VP HEMA1-Chlorohexane 0.3 0.7 33 4-VP PEGMEMA 300 1-Chlorohexane 0.3 0.7 344-VP PEGMEMA 1000 1-Chlorohexane 0.3 0.7 35 4-VP PEGMA 3001-Chlorohexane 0.3 0.7 36 4-VP PEGMA 1100 1-Chlorohexane 0.3 0.7 37 4-VPHEA 1-Chlorohexane 0.3 0.7 38Poly(hydroxyethylene(dimethyliminio)ethylene(dimethyiminio)methylene)dichloride 39Poly(oxy-1,2-ethanediyl(dimethylimino)-1,2-ethanediyl(dimethylimino)-1,2-ethanediyl dichloride) 40 2-Propen-1-aminium,N,N-dimethyl-N-2-propenyl-, chloride, homopolymer 41Poly(iminoimidocarbonyliminoimidocarbonyliminohexamethylene)hydrochloride 42Poly(oxy-1,2-ethanediyl),.alpha.,.alpha.′-((((1,2,3,4,4a,9,10,10a-octahydro-1,4a-dimethyl-7-(1-methylethyl)-1-phenanthrenyl)methyl)imino)di-2,1 -ethanediyl)bis(.omega.-hydroxy-, (1R-(1-.alpha.,4a.beta.,10a.alpha.))-HEMA: 2-hydroxyethylmethacrylate PEGMA: poly(ethylene glycol)methacrylate, number indicates the average molecular weight of themonomer PEGMEMA: poly(ethylene glycol)methyl ether methacrylate, numberindicates the average molecular weight of the monomer HEA:2-hydroxyethyl acrylate DMAA: 1,3-dimethylallylamine

TABLE 1b Examples of small molecule cationic antimicrobial compounds foruse in the invention No. R1 R2 R3 R4 X− Y+ 18 2-hydroxyethyl2-hydroxyethyl 2-hydroxyethyl benzyl chloride N 19 benzyl 2-hydroxyethyl2-hydroxyethyl decyl chloride N 20 benzyl 2-hydroxyethyl 2-hydroxyethyldodecyl chloride N 21 benzyl 2-hydroxyethyl 2-hydroxyethyl hexadecylchloride N 22 benzyl 2-hydroxyethyl 2-hydroxyethyl octadecyl chloride N23 benzyl 2-hydroxyethyl 2-hydroxyethyl octyl chloride N 24 benzyl2-hydroxyethyl 2-hydroxyethyl tetradecyl chloride N 25 hydroxymethylhydroxymethyl hydroxymethyl hydroxymethyl sulfate P 26 methyl2-hydroxyethyl 2-hydroxyethyl decyl chloride N 27 methyl 2-hydroxyethyl2-hydroxyethyl dodecyl chloride N 28 methyl 2-hydroxyethyl2-hydroxyethyl hexadecyl chloride N 29 methyl 2-hydroxyethyl2-hydroxyethyl octadecyl chloride N 30 methyl 2-hydroxyethyl2-hydroxyethyl octyl chloride N 31 methyl 2-hydroxyethyl 2-hydroxyethyltetradecyl chloride N 32 methyl Benzyl decyl decyl chloride N 33 methylBenzyl dodecyl dodecyl chloride N 34 methyl Benzyl hexadecyl hexadecylchloride N 35 methyl Benzyl octadecyl octadecyl chloride N 36 methylBenzyl tetradecyl tetradecyl chloride N 37 methyl Methyl3,4-dichlorobenzyl decyl chloride N 38 methyl Methyl 3,4-dichlorobenzyldodecyl chloride N 39 methyl Methyl 3,4-dichlorobenzyl hexadecylchloride N 40 methyl Methyl 3,4-dichlorobenzyl octadecyl chloride N 41methyl Methyl 3,4-dichlorobenzyl octyl chloride N 42 methyl Methyl3,4-dichlorobenzyl tetradecyl chloride N 43 methyl Methyl 5-hydroxy-4-oxo- decyl chloride N 2(4H)- pyranylmethyl 44 methyl Methyl 5-hydroxy-4-oxo- dodecyl chloride N 2(4H)- pyranylmethyl 45 methyl Methyl5 -hydroxy-4-oxo- hexadecyl chloride N 2(4H)- pyranylmethyl 46 methylMethyl 5 -hydroxy-4-oxo- octadecyl chloride N 2(4H)- pyranylmethyl 47methyl Methyl 5 -hydroxy-4-oxo- octyl chloride N 2(4H)- pyranylmethyl 48methyl methyl 5 -hydroxy-4-oxo- tetradecyl chloride N 2(4H)-pyranylmethyl 49 methyl Methyl benzyl decyl chloride N 50 methyl Methylbenzyl dodecyl bromide N 51 methyl Methyl benzyl dodecyl chloride N 52methyl Methyl benzyl dodecyl naphthenate N 53 methyl Methyl benzyldodecyl saccharinate N 54 methyl Methyl benzyl hexadecyl chloride N 55methyl Methyl benzyl hexadecyl saccharinate N 56 methyl Methyl benzyloctadecyl chloride N 57 methyl Methyl benzyl octyl chloride N 58 methylMethyl benzyl tetradecyl chloride N 59 methyl Methyl benzyl tetradecylsaccharinate N 60 methyl Methyl decyl decyl bicarbonate N 61 methylMethyl decyl decyl carbonate N 62 methyl Methyl decyl decyl chloride N63 methyl Methyl decyloxypropyl decyloxypropyl chloride N 64 methylMethyl dimethylbenzyl dodecyl chloride N 65 methyl Methyl dimethylbenzylhexadecyl chloride N 66 methyl Methyl dimethylbenzyl octadecyl chlorideN 67 methyl Methyl dimethylbenzyl tetradecyl chloride N 68 methyl Methyldodecyl dodecyl chloride N 69 methyl Methyl dodecylbenzyl dodecylchloride N 70 methyl Methyl dodecylbenzyl tetradecyl chloride N 71methyl Methyl ethyl cetyl bromide N 72 methyl Methyl ethyl dodecylbromide N 73 methyl Methyl ethyl dodecyl bromide N 74 methyl Methylethyl hexadecyl bromide N 75 methyl Methyl ethyl octadecyl bromide N 76methyl Methyl ethyl tetradecyl bromide N 77 methyl Methyl ethylbenzyldodecyl chloride N 78 methyl Methyl ethylbenzyl dodecyl cyclohexylsulf Namate 79 methyl Methyl ethylbenzyl hexadecyl chloride N 80 methyl Methylethylbenzyl hexadecyl cyclohexylsulf N amate 81 methyl Methylethylbenzyl octadecyl chloride N 82 methyl Methyl ethylbenzyl octadecylcyclohexylsulf N amate 83 methyl Methyl ethylbenzyl tetradecyl chlorideN 84 methyl Methyl ethylbenzyl tetradecyl cyclohexylsulf N amate 85methyl Methyl hexadecyl hexadecyl chloride N 86 methyl Methyl isononyldecyl chloride N 87 methyl Methyl isopropylbenzyl dodecyl chloride N 88methyl Methyl isopropylbenzyl hexadecyl chloride N 89 methyl Methylisopropylbenzyl octadecyl chloride N 90 methyl Methyl isopropylbenzyltetradecyl chloride N 91 methyl Methyl lauryl lauryl bromide N 92 methylMethyl methyl 3-dodecyl-2- chloride N hydroxypropyl 93 methyl Methylmethyl 3-pentadecyl-2- chloride N hydroxypropyl 94 methyl Methyl methyl3-tetradecyl-2- chloride N hydroxypropyl 95 methyl Methyl methyl3-tridecyl-2- chloride N hydroxypropyl 96 methyl Methyl methyl cetylbromide N 97 methyl Methyl methyl dodecyl bromide N 98 methyl Methylmethyl dodecyl chloride N 99 methyl Methyl methyl dodecylbenzyl chlorideN 100 methyl Methyl methyl hexadecyl bromide N 101 methyl Methyl methylhexadecyl chloride N 102 methyl Methyl methyl methyldodecyl chloride Nbenzyl 103 methyl Methyl methyl octadecyl bromide N 104 methyl Methylmethyl octadecyl chloride N 105 methyl Methyl methyl tetradecyl bromideN 106 methyl Methyl methyl tetradecyl chloride N 107 methyl Methylmethylbenzyl dodecyl chloride N 108 methyl Methyl methylbenzyltetradecyl chloride N 109 methyl Methyl octadecyl octadecyl chloride N110 methyl Methyl octyl octyl chloride N 111 methyl Methyloctyloxypropyl octyloxypropyl chloride N 112 methyl Methyl tetradecyltetradecyl chloride N 113 Morpholinium ethyl tetradecyl sulfate N 114Morpholinium ethyl hexadecyl sulfate N 115 Morpholinium ethyl octadecylsulfate N 116 Morpholinium ethyl cetyl sulfate N 117Methylisoquinolinium dodecyl chloride N 118 Methylisoquinoliniumtetradecyl chloride N 119 Methylisoquinolinium hexadecyl chloride N 120Methylisoquinolinium octadecyl chloride N 121 Pyridinium cetyl bromide N122 Pyridinium cetyl chloride N

TABLE 2 examples of anionic surfactants for use in the invention ASAnionic surfactant A Caproic acid B Caprylic acid C Capric acid DUndecylenic acid E Lauric acid F Myristic acid G Palmitic acid H Stearicacid I p-toluenesulfonic Acid Monohydrate J Dodecyl sulfonate KBenzenesulfonate L Dodecylbenzene sulfonate M Hexylphosphonate Ndodecylphosphonate O octadecylphosphonate P Methyl hexylphosphonate QMethyl dodecylphosphonate R Methyl octadecylphosphonate S lauryl sulfateT sodium lauryl sulfate U dodecyl sulfate V sodium dodecyl sulfate Wbenzoic acid X sodium benzoate Y Octyl benzoic acid Z glycolic acid AAoctadeca-dienoic acid

TABLE 3a Examples of polymeric complexes for use in the inventionComplex CAC Amount AS Amount No. No. (g) letter (g)  1  1 28.5 A 11.6  2 2 30.4 B 14.4  3  3 38.1 C 17.2  4  4 30.4 D 18.4  5  5 39.2 E 20.0  6 6 28.3 F 22.8  7  7 35.7 G 25.6  8  8 47.0 H 28.4  9  9 93.7 I 19.0 1010 47.0 J 25.0 11 11 100.4 K 15.8 12 12 34.8 L 32.6 13 13 57.4 M 16.6 1414 97.0 N 25.0 15 15 260.4 O 33.4 16 16 97.0 P 18.0 17 17 283.7 Q 26.418 18 54.1 R 34.8 19 19 20.7 S 26.6 20 20 24.0 T 28.8 21 21 25.9 U 26.622 22 33.7 V 28.8 23 23 25.9 W 12.2 24 24 34.8 X 14.4 25 25 23.9 Y 23.426 26 31.3 Z 7.6 27 27 42.6 AA 28.0 28 28 89.2 A 11.6 29 29 42.6 B 14.430 30 95.9 C 17.2 31 31 30.3 D 18.4 32 32 52.9 E 20.0 33 33 92.6 F 22.834 34 255.9 G 25.6 35 35 92.6 H 28.4 36 36 279.2 I 19.0 37 37 49.7 J25.0 38  3 38.1 A 11.6 39  3 38.1 B 14.4 40  3 38.1 C 17.2 41  3 38.1 D18.4 42  3 38.1 E 20.0 43  3 38.1 F 22.8 44  3 38.1 G 25.6 45  3 38.1 H28.4 46  3 38.1 I 19.0 47  3 38.1 L 32.6 48 38 122.6 F 22.8 49 39 129.6G 25.6 50 40 161.7 H 28.4 51 41 213.3 I 19.0 52 42 461.7 J 25.0

TABLE 3b Small molecule cationic examples of complexes for use in theinvention Complex CAC Amount AS Amount No. No. (g) letter (g)  11 1827.6 A 11.6  12 19 37.2 B 14.4  13 20 40.0 C 17.2  14 21 45.6 D 18.4  1522 48.4 E 20.0  16 23 34.4 F 22.8  17 24 42.8 G 25.6  18 25 20.3 H 28.4 19 26 29.6 I 19.0  20 27 32.4 J 25.0  21 28 29.6 K 15.8  22 29 40.8 L32.6  23 30 26.8 M 16.6  24 31 35.2 N 25.0  25 32 43.8 O 33.4  26 3349.4 P 18.0  27 34 60.6 Q 26.4  28 35 66.3 R 34.8  29 36 55.0 S 26.6  3037 38.1 T 28.8  31 38 40.9 U 26.6  32 39 38.1 V 28.8  33 40 49.3 W 12.2 34 41 35.3 X 14.4  35 42 43.7 Y 23.4  36 43 34.6 Z 7.6  37 44 37.4 AA28.0  38 45 43.0 A 11.6  39 46 45.8 B 14.4  40 47 31.8 C 17.2  41 4840.2 D 18.4  42 49 31.2 E 20.0  43 50 38.4 F 22.8  44 51 34.0 G 25.6  4552 71.5 H 28.4  46 53 48.8 I 19.0  47 54 39.6 J 25.0  48 55 54.4 K 15.8 49 56 42.4 L 32.6  50 57 28.4 M 16.6  51 58 36.8 N 25.0  52 59 51.6 O33.4  53 60 38.8 P 18.0  54 61 38.7 Q 26.4  55 62 36.2 R 34.8  56 6347.8 S 26.6  57 64 36.8 T 28.8  58 65 42.4 U 26.6  59 66 45.2 V 28.8  6067 39.6 W 12.2  61 68 41.8 X 14.4  62 69 50.8 Y 23.4  63 70 53.6 Z 7.6 64 71 40.7 AA 28.0  65 72 32.2 A 11.6  66 73 32.2 B 14.4  67 74 37.8 C17.2  68 75 40.7 D 18.4  69 76 35.0 E 20.0  70 77 36.8 F 22.8  71 7851.2 G 25.6  72 79 42.4 H 28.4  73 80 56.8 I 19.0  74 81 31.2 J 25.0  7582 45.6 K 15.8  76 83 39.6 L 32.6  77 84 54.0 M 16.6  78 85 53.0 N 25.0 79 86 34.0 O 33.4  80 87 38.2 P 18.0  81 88 43.8 Q 26.4  82 89 46.6 R34.8  83 90 41.0 S 26.6  84 91 46.3 T 28.8  85 92 32.2 U 26.6  86 9336.4 V 28.8  87 94 35.0 W 12.2  88 95 33.6 X 14.4  89 96 39.2 Y 23.4  9097 30.8 Z 7.6  91 98 26.4 AA 28.0  92 99 35.4 A 11.6  93 100 36.4 B 14.4 94 101 32.0 C 17.2  95 102 36.8 D 18.4  96 103 39.2 E 20.0  97 104 34.8F 22.8  98 105 33.6 G 25.6  99 106 29.2 H 28.4 100 107 41.8 I 19.0 101108 47.4 J 25.0 102 109 58.6 K 15.8 103 110 30.6 L 32.6 104 111 42.2 M16.6 105 112 47.4 N 25.0 106 113 37.6 O 33.4 107 114 40.4 P 18.0 108 11543.2 Q 26.4 109 116 43.2 R 34.8 110 117 36.2 S 26.6 111 118 39.0 T 28.8112 119 41.8 U 26.6 113 120 44.6 V 28.8 114 121 42.6 W 12.2 115 122 38.2X 14.4

TABLE 4 examples of complexes used in coatings and types of coatingsformed Exp. CAC-AS complex No. (ex. # and amount) Type of coating 110-2.5% wt. in dry coating Syntran 1693 (steel coil coating) 2 10-5% wt.in dry coating Porter Paint Base PP13 (latex wall paint) 3 10-5% wt. indry coating SCW-2710 (packaging clear coat #1) 4 10-5% wt. in drycoating Sun Coat W/B Gloss (packaging clear coat #2) 5 10-5% wt. in drycoating Pure Wax (retail floor wax) 6 10-5% wt. in dry coatingPolyurethane varnish (retail water-base) 7 10-100% wt. in dry coatingComplex used as a stand-alone coating 8 10-100% wt. in dry coatingMycroFence AM-216 (proprietary formulation)

TABLE 5 Efficacy of the coating against S. aureus Coating BacteriaExposure % Log Exp. No. Chosen Time Reduction Reduction 1 S. aureus 24hours >99.998% >4.67 2 S. aureus 24 hours >99.998% >4.62 3 S. aureus 24hours >99.998% >4.62 4 S. aureus 24 hours 99.998% 4.62 7 S. aureus 24hours >99.998% >4.67 8 S. aureus 24 hours 98.15% 1.73 8 S. aureus 24hours >99.998 >4.62

Liquid mixture stability was assessed for certain examples providedabove. The dispersion stability for the antimicrobialcompound-containing mixture was comparable to the dispersion stabilityfor a comparative mixture lacking the antimicrobial compound and itsassociated anionic surfactant.

Antimicrobial activity was assessed for selected examples from Table 4.The antimicrobial activity of the cationic antimicrobial compound wasessentially not diminished when incorporated into liquid mixtures andcoatings formed from those mixtures.

Consequently, in view of the disclosure herein, the invention includesbut is not limited to the following:

-   -   1. A composition comprising a mixture of:        -   a. a carrier liquid;        -   b. a first complex of a cationic antimicrobial compound and            a first anionic surfactant dispersed in the carrier liquid;        -   c. a second complex of a second anionic surfactant and at            least one member selected from particles dispersed in the            carrier liquid; and        -   d. said mixture is a suspension, a colloid, a latex, and/or            an emulsion.    -   2. A liquid coating composition comprising a mixture containing        a cationic antimicrobial compound complexed with an associated        first anionic surfactant and wherein the mixture contains more        total surfactant than a comparative liquid coating composition        that is otherwise identical but lacks the cationic antimicrobial        compound and the associated first anionic surfactant.    -   3. A composition comprising a mixture of a carrier liquid and a        complex, wherein the complex has a cationic antimicrobial        polymeric portion and an anionic surfactant-compatibilizing        portion, wherein the complex has an ionic attraction between the        cationic antimicrobial portion and the anionic        surfactant-compatibilizing portion that is greater than an ionic        attraction of either portion to any other ions present in the        liquid carrier, and wherein        -   a. the complex after removal of the liquid carrier has            sufficient antimicrobial activity to substantially reduce            the presence of bacteria; and        -   b. the anionic surfactant-compatibilizing portion suspends            the complex in the carrier liquid; and        -   c. the mixture without addition of the complex is a            suspension, latex, or colloid; and        -   d. the mixture remains as a suspension, latex, or colloid            with addition of the complex.    -   4. A composition comprising a dispersion of a plurality of        dispersible antimicrobial complexes that comprise ions of a        cationic antimicrobial compound in a carrier liquid, wherein the        ions of the cationic antimicrobial molecules in the carrier        liquid are complexed to ions of a first anionic surfactant,        wherein the dispersion has ions of a second anionic surfactant,        and the ions of the first anionic surfactant have an ionic        attraction greater in magnitude than an ionic attraction of the        ions of the second anionic surfactant to the ions of the        cationic antimicrobial compound.    -   5. A method of making a coating material comprising        -   a. dispersing a complex of a cationic antimicrobial compound            and a first anionic surfactant in a carrier liquid            containing a second anionic surfactant;        -   b. wherein an affinity of the cationic antimicrobial            compound for the first anionic surfactant is greater than or            equal to an affinity of the cationic antimicrobial compound            for the second anionic surfactant.    -   6. A method of making a second latex comprising mixing a first        latex having a dispersed binder with a cationic antimicrobial        compound and a first anionic surfactant.    -   7. A method of using a first anionic surfactant comprising        -   a. adding a cationic antimicrobial compound to a mixture            that includes a second anionic surfactant, wherein the            cationic antimicrobial compound destabilizes a disperse            phase in the mixture in the absence of addition of the first            anionic surfactant and the mixture is a latex, a suspension,            or a colloid; and        -   b. adding the first anionic surfactant to the mixture to            prevent the cationic antimicrobial compound from            destabilizing the disperse phase in the mixture.    -   8. A composition or method of any paragraph above, wherein the        cationic antimicrobial compound is polymeric.    -   9. A composition or method of paragraph 8, wherein the cationic        antimicrobial compound is hydrophilic.    -   10. A composition or method of paragraph 9, wherein the        antimicrobial compound has a discrete hydrophilic domain.    -   11. A composition or method of paragraph 10, wherein the        discrete hydrophilic domain comprises PEGMA.    -   12. A composition or method of paragraph 11, wherein the PEGMA        comprises PEGMEMA.    -   13. A composition or method of any of paragraphs 8-12, wherein        the cationic antimicrobial compound comprises an        alkyl-quaternized nitrogen.    -   14. A composition or method of paragraph 13, wherein the        cationic antimicrobial compound comprises a copolymer of        alkyl-quaternized vinyl pyridine and a hydrophilic comonomer.    -   15. A composition or method of paragraph 14, wherein the alkyl        is an alkyl having between 4 and 12 carbon atoms.    -   16. A composition or method of paragraph 14 or paragraph 15,        wherein the alkyl-quaternized vinyl pyridine is        alkyl-quaternized 4-vinyl pyridine and the hydrophilic comonomer        comprises a polymer of PEGMA.    -   17. A composition or method of paragraph 14 or paragraph 15,        wherein the alkyl-quaternized vinyl pyridine is        alkyl-quaternized 2-vinyl pyridine and the hydrophilic comonomer        comprises a polymer of PEGMA.    -   18. A composition or method of paragraph 16 or paragraph 17,        wherein the polymer of PEGMA comprises PEGMEMA.    -   19. A composition or method of any of paragraphs 13-18, wherein        the alkyl group comprises a linear butyl group.    -   20. A composition or method of any of paragraphs 13-18, wherein        the alkyl group comprises a linear hexyl group.    -   21. A composition or method of any of paragraphs 1-7, wherein        the cationic antimicrobial compound is not a polymer.    -   22. A composition or method of paragraph 21, wherein the        cationic antimicrobial compound has a hydrophilic domain.    -   23. A composition or method of paragraph 21 or paragraph 22,        wherein the discrete hydrophilic domain comprises PEGMA.    -   24. A composition or method of paragraph 23, wherein the PEGMA        comprises PEGMEMA.    -   25. A composition or method of any of paragraphs 8-12 and 21-24,        wherein the cationic antimicrobial compound comprises an        alkyl-quaternized nitrogen.    -   26. A composition or method of any paragraph above, wherein the        first anionic surfactant is sufficiently hydrophilic to suspend        the cationic antimicrobial compound in water.    -   27. A composition or method of paragraph 9, wherein the first        anionic surfactant and the hydrophilic cationic antimicrobial        compound together suspend the cationic antimicrobial compound in        water.    -   28. A composition or method of any paragraph above, wherein the        first anionic surfactant comprises a phosphonate, a sulfonate, a        sulfate monoester, a benzoate, a carboxylate, or a glycolic        moiety.    -   29. A composition or method of paragraph 28, wherein the first        anionic surfactant comprises a sulfonate and/or a carboxylate.    -   30. A composition of any of paragraphs 26-29, wherein the first        anionic surfactant has a hydrophobic portion having at least 6        carbon atoms.    -   31. A composition of paragraph 30, wherein the first anionic        surfactant has a hydrophobic portion having at least 8 carbon        atoms.    -   32. A composition of any paragraph above, wherein the first        anionic surfactant has a hydrophobic portion having an aromatic        group.    -   33. A composition of paragraph 32, wherein the aromatic group        has an alkyl substituent.    -   34. A composition of paragraph 33, wherein the alkyl substituent        is hydrophobic and has at least 6 carbon atoms.    -   35. A composition of paragraph 34, wherein the alkyl substituent        has 12 or fewer carbon atoms in linear or branched        configuration.    -   36. A composition or method of any paragraph above, wherein the        carrier liquid is water.

The examples and discussion above focus on water as the carrier liquid.However, examples and discussion above are equally applicable to anorganic liquid such as an oil being the carrier liquid.

All patents, applications, and other publications mentioned herein areincorporated by reference in their entirety for all purposes, as if eachwas put forth in full herein.

What is claimed is:
 1. A composition comprising a mixture of: (a) acarrier liquid; (b) a first complex of a cationic antimicrobial compoundand a first anionic surfactant dispersed in the carrier liquid; (c) asecond complex of a second anionic surfactant and at least one memberselected from particles and immiscible droplets dispersed in the carrierliquid; and (d) said mixture is a colloid, a suspension, or a latex; andwherein (e) the cationic antimicrobial compound comprises a copolymer ofa quaternized nitrogen-containing monomer and a hydrophilic comonomer,wherein (f) the quaternized nitrogen-containing monomer comprises analkyl-quaternized 4-vinyl pyridine, and (g) the hydrophilic comonomercomprises a poly(ethylene glycol) methacrylate.
 2. The composition ofclaim 1, wherein the alkyl group of the alkyl-quaternized 4-vinylpyridine has between 4 and 12 carbon atoms.
 3. The composition of claim2, wherein the alkyl group comprises a linear butyl group.
 4. Thecomposition of claim 2, wherein the alkyl group comprises a linear hexylgroup.
 5. The composition of claim 1, wherein the carrier liquidcomprises water, and the first anionic surfactant is sufficientlyhydrophilic to suspend the copolymer in the water.
 6. The composition ofclaim 5, wherein the hydrophilic comonomer and the first anionicsurfactant together are sufficient to suspend the copolymer in thewater, and each of the hydrophilic comonomer and the first anionicsurfactant alone are insufficient to suspend the copolymer in the water.7. The composition of claim 1, wherein the first anionic surfactantcomprises a phosphonate, a sulfonate, a sulfate monoester, a benzoate, acarboxylate, or a glycolic moiety.
 8. The composition of claim 7,wherein the first anionic surfactant has a greater affinity for thecopolymer than any other anions present in the carrier liquid.
 9. Thecomposition of claim 7, wherein the first anionic surfactant has ahydrophobic portion having at least 6 carbon atoms.
 10. The compositionof claim 9, wherein the hydrophobic portion of the first anionicsurfactant has at least 8 carbon atoms.
 11. The composition of claim 7,wherein the first anionic surfactant has a hydrophobic portion having anaromatic group.
 12. The composition of claim 11, wherein the aromaticgroup has a hydrophobic substituent having at least 6 carbon atoms. 13.The composition of claim 12, wherein the hydrophobic substituentcomprises an alkyl group.
 14. The composition of claim 8, wherein thealkyl group of the alkyl-quaternized 4-vinyl pyridine has at least 4carbon atoms.
 15. The composition of claim 9, wherein the alkyl group ofthe alkyl-quaternized 4-vinyl pyridine has at least 4 carbon atoms. 16.The composition of claim 10, wherein the alkyl group of thealkyl-quaternized 4-vinyl pyridine has at least 4 carbon atoms.
 17. Thecomposition of claim 11, wherein the alkyl group of thealkyl-quaternized 4-vinyl pyridine has at least 4 carbon atoms.
 18. Thecomposition of claim 12, wherein the alkyl group of thealkyl-quaternized 4-vinyl pyridine has at least 4 carbon atoms.
 19. Thecomposition of claim 13, wherein the alkyl group of thealkyl-quaternized 4-vinyl pyridine has at least 4 carbon atoms.
 20. Thecomposition of claim 1, wherein the hydrophilic comonomer comprises atleast one member selected from the group consisting of poly(ethyleneglycol) methacrylate and poly(ethylene glycol) methyl ethermethacrylate.